This invention relates to automatically closing ambient air breathing devices, generally useful with breathable air systems in hostile breathing environments. The device of the invention is particularly useful in association with underwater breathing apparatus, enabling the passage of ambient air to the user as desired, and automatically interrupting such passage when the ambient environment is hostile.
The use of breathing systems in a non-breathable environment is well known. Breathable air systems are commonly used in high altitude aircraft, underwater diving, fire-fighting and various emergency situations wherein the surrounding environment is fouled or otherwise unsuitable for breathing. In the modern era, breathable air systems generally use full or partial face-mask and the like devices to conveniently supply the breathable air to the user upon demand. Such devices generally protect the user""s eyes and face from the hostile environment and allow the user to keep his mouth free for communications and the like, by relying upon the attaining and maintaining of a reliable seal around a perimeter of the face, particularly the mouth and nose. To attain a reliable seal, the mask generally requires careful preparation, placement and fitting to the user and is not quickly and easily refitted upon removal.
Breathable air systems are generally uncomfortable under the best of circumstances and many breathable air assemblies comprise self-contained compressed air apparatus, enabling a user to move to and from a hostile environment under a work regiment wherein it is inconvenient to remove and refit a face-mask. Self-contained compressed air systems, have a limited supply of air, but are desired in many environments, the air being generally uncomfortable to breath in that it has a drying effect upon the mouth and throat of the user thus complicating the comfort of the user.
For the convenience and comfort of the user, ambient air devices have been developed which enable the user to manually switch to and from breathing air from a compressed or alternate air source and the ambient air, without removal of the breathing equipment. Such ability can reduce the rate of depletion of a limited supply of compressed air while at the same time provide relief from the drying effects of such compressed air. In many applications however, there are circumstances wherein the user may be in an ambient air breathing mode and without warning, or because of an incapacitation or the like, the user is unable to manually switch from the ambient air breathing mode to the compressed air system mode. For example, in the case of high speed watercraft racing, aircraft failure or other accident or the like, the user may be rendered disoriented, unconscious or otherwise unable to manually switch from the ambient air source to a compressed or other alternate air supply. Thus, there is a need for an ambient air device which automatically closes without manual action being taken by the user to switch from ambient breathing to compressed air or alternate air supply system.
It is an object of the present invention to provide a ambient air device which is convenient for use and durable in operation.
It is another object of the invention to provide an ambient air device which can be easily mounted to a face-mask and the like.
It is further object of the invention to provide an ambient air device which will automatically interrupt the supply of ambient air in emergency situations.
These and other objects of the invention will be apparent from the following description of the invention.
In accordance with the present invention, an automatically closing ambient air device is disclosed, comprising a housing having a generally conical passageway with an inlet for the flow of fluid from the ambient environment into the conical passageway and an outlet for the flow of fluid from the passageway to the user. The outlet to the user comprises valve means arranged to be actuated to close fluid flow from the passageway by buoyant force and/or gravitational movement of a weighted element in response to the spacial orientation of the conical wall of the passageway to level.
In a preferred embodiment of the invention, the generally conical passageway is arranged about a central axis, with the valved outlet being arranged toward or about at the base of the cone. A weighted element is arranged in the passageway to move toward and away from the base of the cone to engage and disengage the valve means and actuate closing, depending upon the orientation of the conical walls of the passageway to level. In a particularly preferred embodiment, the weighted element comprises a plurality of weighted balls which roll along the conical wall of the passageway toward or away from the base end of the passageway, in response to the spacial orientation of the conical wall of the passageway to level, to assist engagement of the valve means.
In a further preferred embodiment of the invention, the passageway comprises an axle, mounted at about opposite ends thereof within the passageway and extending along about a central axis of the passageway. The valve means comprises a buoyant element which is slidably mounted on the axle, arranged to slide axially along the axle from a first position spaced from the outlet being an open valve position, to a second position arranged to seal the outlet from the flow of fluid therethrough being the closed valve position.
In one embodiment, means are provided to manually engage the buoyant element to enable manually sliding the buoyant element from about the first position to the second position on the axle. The weighted element is arranged in the passageway between the buoyant element and the vertex end of the passageway, being arranged to assist movement of the buoyant element when the first position of the buoyant element is higher or about the same level in spacial orientation with the second position.
In a further preferred embodiment, the buoyant element comprises a flexible elastomeric surface, which is arranged to engage against a mating surface surrounding the opening of the outlet, so as to seal the flow of fluid from the passageway through the opening. In a particularly preferred embodiment, the outlet comprises a plurality of openings arranged around the central axis of the passageway, an end of the axle is mounted to structure crossing about the diameter of the passageway, and the buoyant element comprises a flexible elastomeric diaphragm arranged to engage a surface adjacent the plurality of openings so as to seal the flow of fluid through the openings.
In a particularly preferred embodiment, the shape of the housing defines the generally conical passageway and comprises a plurality of inlet openings therethrough arranged to enable flow of ambient air and/or ambient liquid into the passageway. The outlet of the passageway is positioned at the base of the conical passageway, and is arranged generally around the central axis of the passageway and is enabled for connection to a tubular conduit for the flow of ambient air from the conical passageway to the user. In a most preferred embodiment, the outlet comprises a plurality of openings in the base of the cone surrounding the outlet from the passageway.
In a particularly preferred embodiment the buoyant element comprises a generally cylindrical structure formed from and/or containing buoyant material, which is axially mounted along a generally central axle of the passageway. An end of the buoyant element is configured to sealingly engage a mating seat at about the outlet, to resist the flow of fluid from the passageway through the outlet. In a particularly preferred embodiment the end of the buoyant element comprises a flexible diaphragm which engages against an opening of the outlet to enable sealing the outlet.
It should be understood that the present invention contemplates multiple further diverse configurations and arrangements for automatically closing an outlet in accord with the spirit of the invention wherein buoyant force is assisted by gravitational force to seal an outlet of an ambient air device from passage of fluids. Thus for example, the buoyant element may comprise a ball and seat or the like arrangement for closing the outlet. The gravitation force may be exerted by a levered arrangement engaging the buoyant element rather than the preferred arrangement of the invention. These and other embodiments of the invention will be apparent from the following detailed description of the invention.